Machines, such as motor graders, are generally used for clearing materials, such as snow, accumulated on road surface or any other ground surfaces. For example, the motor grader includes an implement, such as a snow wing plow, attached to a frame of the motor grader in proximity to an operator cabin. The implement is coupled to the motor grader in a manner to extend a lateral snow plowing reach of the motor grader. In addition, the implement extends at an angle to a longitudinal axis of the motor grader for engaging with the ground surface. During snow plowing, an operator of the motor grader needs to watch for obstacles along the ground surface and raise the implement, to avoid striking the obstacles. However, in cases where the obstacles are buried by snow, or visibility is otherwise poor making it difficult for the operator to see the obstacle, striking of the implement with the obstacles may lead to application of high magnitude load on the implement. Accordingly, there is a need for the implement to uncouple from the frame of the machine to withstand the applied load and prevent the load from being transmitted to the frame of the machine.
JP Patent Number 3170683 (the '683 patent) discloses separated pieces of a shear pin from falling by freely fitting C-shaped rings into grooves in shear pin bushes so that inner diameters of the rings are slightly smaller than an outer diameter of the shear pin. The C-shaped rings are freely fitted into fitting grooves for the C-shaped rings inside of shear pin bushes. When the shear pin is inserted into the C-shaped rings, a suitable tightening force is generated by an elastic action of the C-shaped rings, and tightens and holds the shear pin. After the insertion, the shear pin is fixed at a position by a lock pin. In the shear pin bushes, side faces with high hardness agrees with shearing grooves of the shear pin by heat treatment. When the shear pin reaches the limitation of its shearing stress caused by overload on a body, the shear pin is sheared and separated.